Construction on tower 3, which is scheduled for completion in 2015, has reached ground level.

"If you look at the building now you can see the size and heft of some of these concrete walls that surround the court. That is a unique safety feature of these buildings. These buildings are built like no other buildings in the Unites States," said Janno Lieber, World Trade Center Project Developer.

While the Memorial Pools and their 30-foot high cascading waterfalls provide a serene setting for visitors, the names of the victims are written on bronze plaques around the pools.

The architect says that's what means the most to him.

"We were able to put names side by side. Names of friends, co-workers, family members. People who might have perished together that day and didn't know one another before that," said Michael Arad, 9/11 Memorial Architect.

Monica Iken's husband was one of those who perished. "For me this memorial is what it's all about. For me to be able to come here and finally honor him," Iken said.

The National September 11th Memorial will open to the public on September 12th.